地震边坡稳定性有限元塑性极限分析拟动力法研究
Assessment of rigorous solutions for pseudo-dynamic slope stability:Finite-element limit-analysis modelling
周建烽 1郑子玉 1鲍挺 2涂兵雄 1俞剑 3覃长兵4
作者信息
- 1. College of Civil Engineering,Huaqiao University,Xiamen 361021,China
- 2. School of Civil Engineering,Chongqing University,Chongqing 400045,China
- 3. School of Civil Engineering,Tongji University,Shanghai 200092,China
- 4. School of Civil Engineering,Chongqing University,Chongqing 400045,China;Chongqing Field Scientific Observation Station for Landslide Hazards in Three Gorges Reservoir Area,Chongqing 400045,China
- 折叠
摘要
地震诱发边坡失稳是地震灾害的主要类型之一,开展地震作用下边坡稳定性研究具有重要意义.常规拟静力法无法准确模拟地震波在边坡土体中传播的时间和空间效应,难以真实反映地震荷载.本文采用拟动力法模拟地震动荷载输入,基于塑性极限分析下限定理,结合有限元离散技术,建立了满足静力平衡条件、屈服条件、应力边界条件和间断条件的地震边坡稳定性有限元极限分析下限法数学规划模型,基于内点算法寻求边坡超载系数和安全系数的下限解.通过对典型边坡算例分析,验证了本文方法的正确性.进一步分析了均质土边坡、抗剪强度参数随深度线性增加的非均质土边坡以及双层土边坡的地震稳定性,讨论了关联和非关联流动准则对地震边坡稳定性的影响.结果表明:拟静力法和非关联流动法则会低估地震边坡稳定性;边坡安全系数有限元极限分析下限解与上限解之间的差异小于4.5%,本文方法计算结果接近地震边坡稳定性真解.
Abstract
This study developed a finite-element lower-bound procedure to investigate seismic slope stability in homogeneous and non-homogeneous soils.In order to account for dynamic earthquake inputs,horizontal and vertical accelerations are expressed by the pseudo-dynamic approach,in the form of sinusoidal functions.Within the framework of lower-bound theory,the seismic slope stability analysis is transformed to a linear programming problem subjected to:stress equilibrium,stress discontinuity,stress boundary and yield conditions.An interior-point algorithm implemented into MATLAB was adopted to seek optimal lower-bound solutions of slope bearing capacity and safety factor.The proposed procedure for lower-bound analysis of seismic slope stability was validated by comparing the slope safety factor obtained from different approaches including limit equilibrium and Abaqus.A nonuniform soil slope with linearly varied and layered soil strength parameters and non-associated flow rule are considered,and the corresponding effects on seismic slope stability are discussed.The true solution of safety factor to seismic slope stability is well assessed by rigorous lower and upper bounds with the discrepancy no greater than 4.5%.
关键词
地震边坡稳定性/有限元极限分析/拟动力法/真解Key words
seismic slope stability/finite-element limit-analysis modelling/pseudo-dynamic approach/true solution引用本文复制引用
基金项目
National Natural Science Foundation of China(52009046)
National Natural Science Foundation of China(52108302)
Fundamental Research Funds for the Central Universities,China(ZQN-914)
Collaborative Innovation Platform of Fuzhou-Xiamen-Quanzhou National Self-Innovation Zone,China(3502ZCQXT2022002)
Natural Science Foundation of Shanghai,China(23ZR1468500)
出版年
2023
NETL
NSTL
维普
万方数据